1. Field of the Invention
The present invention relates to orthopaedic devices, and more particularly, to orthopaedic implants.
2. Description of the Related Art
Orthopaedic implants are known that are implanted into the body to achieve various surgical objectives. Such implants include bone pins, bone screws and bone plates. The implantation period of the implant can vary from a short period, such as a couple of days, to the end of a patient's life. During the implantation period, the implant will experience natural forces caused by surrounding anatomy structures due to static and dynamic conditions of the anatomy structures. These natural forces can cause the implant to either loosen from the implantation site or, worse, ultimately detach from the implant site.
To prevent the loosening and detachment of an orthopaedic implant from its implantation site, the implant is usually fixated to the implantation site by bone screws, which must be screwed into the implantation site. The implant can also be bonded to the implantation site with an adhesive, such as bone cement, or materials can be attached to the implant that encourage natural ingrowth of tissue onto or into the implant. Natural tissue ingrowth will help to fixate the implant in place and can form a strong bond with the implant.
One problem that arises with implanted devices is that there is a risk that a revision surgery, to remove the implant, may be required due to reasons such as an incorrect placement, an unforeseen event or an infection causing the implant to prematurely fail. In such cases, removing the implant can be a traumatic event for anatomy structures around the site if a lot of force is required to loosen the implant and remove it.
A similar problem can occur with devices that are meant to be temporary, i.e., have a relatively short implantation period. The device can become too integrated with the body and become very difficult to remove, which can lead to trauma at the implantation site during removal.
What is needed in the art is an orthopaedic implant that can resist natural pull out but does not require excessive force to remove.